Abstract: AIM: To explore the effectiveness and mechanism of lymph node tracing using irinotecan coupled with methylene blue in radical resection of advanced gastric cancer.METHODS: 90 patients with advanced gastric cancer were randomly divided into the non-tracing group (n=31), methylene blue tracing group (n=30) and the combination tracing group (n=29). During operation, 2 mL of methylene blue was injected into the peritumoral subserosa at 4 points with microacupuncture needle in methylene blue tracing group, and the couplant of 40 mg of irinotecan and 2 mL methylene blue was injected in combination tracing group. The D₂/D₂⁺ lymphadenectomy was finished by curettage-aspiration dissection with Peng's multifunction operative dissector (PMOD) in all three groups. The operation time, intraoperative hemorrhage quantity, blood transfusion amount, the number of cleared lymph node and postoperative data of follow-up were collected.RESULTS: The average surgery time in three groups were (218±67),(192±31)and (205±36)min(P＞0.05), respectively. The intraoperative average hemorrhage quantity were(248±116),(164±88) and(173±98)mL(P＜0.05), and average blood transfusion amount of recipient's(457±159),(489±176)and (467±148) mL(P＞0.05), respectively. The average numbers of cleared lymph node were (22±9),(22±10) and(30±9)(P＜0.05) with positive lymph node(7±3),(6±3)and(9±3)(P＜0.05), respectively. By an average of 3 years of follow-up, the information of 29, 28 and 28 patients in three groups were collected respectively. The tumor recurrence rates were 31.0%(9/29), 32.1%(9/28) and 21.4%(6/28)(P＞0.05) in three groups while 3-year survival rates were 62.1%(18/29), 57.1%(16/28) and 78.6%(22/28) (P＞0.05), respectively.CONCLUSION: It is not only safe and convenient to inject the couplant of irinotecan and methylene blue into the peritumoral subserosa, but also significantly improve the effectiveness of lymphadenectomy in advanced gastric cancer. The possible mechanism is that the couplant obviously lengthens the dyeing and fading time of lymph nodes, gives color visual stimulation to the surgeon for exact and thorough lymph node dissection all the time during operation.

Key words: Gastric cancer, Lymphadenectomy, Irinotecan, Methylene blue, Tracer agents